Bug Sensors Could Slow Infection, Defend Crops

RIVERSIDE, Calif. and SAO PAULO, Brazil, May 1, 2014 — Better classification of insects in the wild could be a key to protecting crops and halting the spread of diseases.

A team from the University of California, Riverside, in collaboration with the University of Sao Paulo and ISCA Technologies, has developed an optical technique to differentiate species of insects with up to 99 percent accuracy.

Scientists can study insects more accurately with the new sensor device.
“We set out not knowing what was possible,” said Eamonn Keogh, a computer science professor at UC Riverside Bourns College of Engineering. “Now, the problem is essentially solved. We have created insect classification tools that can outperform the world's top entomologists in a fraction of the time.”

Keogh and colleagues created a wireless optical sensor that consists of a phototransistor array and a laser. Its original design used Lego toys, a cheap laser pointer and part of a TV remote control.

The sensors identify insects by analyzing the patterns generated when wings partially block the laser beams. The signals are filtered and amplified, fed into a digital sound recorder and later downloaded to a computer for analysis.
Six insect species were examined.

In a separate experiment, the researchers tested classification accuracy by adding an increasing number of species. With two species, they had 99 percent accuracy. That percentage declined to 96 percent with five species and to 79 percent with 10 species.

This device employs the new classification technique created to collect data on insect behavior. Courtesy of UC Riverside.
The new method has generated larger amounts of data than previous methods. Researchers said it has the potential to help farmers protect their crops from insect damage, as well as limit the spread of insect-borne diseases such as malaria and Dengue fever by facilitating better targeting of pesticides.

The new classification technique is simple and inexpensive, according to the researchers, while also offering digital advantages such as higher accuracy, real-time monitoring and the option to gather additional flight behavior patterns. Keogh expects that such sensors could be built for less than $10 and potentially be solar or battery powered.

The sensors are now in small-scale use in Hawaii and Brazil, and will soon be deployed in Mali, thanks to collaboration with the Laboratory of Malaria and Vector Research at the National Institute of Allergy and Infectious Diseases in Rockville, Md. Keogh hopes to expand the sensors’ use to regions worldwide within the next few years.

The work was supported by the Vodafone Americas Foundation, the Bill and Melinda Gates Foundation and the São Paulo Research Foundation. The research is under review by the Journal of Insect Behavior for future publication.